1. Field
The present disclosure relates generally to a satellite-signal receiving system. More specifically, the present disclosure relates to a system capable of receiving signals from all four global navigation satellite systems (GNSSs).
2. Related Art
In recent years, the proliferation of portable satellite-signal-receiving devices has resulted in an expansion of the usage of satellite navigation from the military domain to various aspects of civilian life. For example, nowadays most smartphones are equipped with built-in Global Positioning System (GPS) receivers that enable real-time position tracking and direction guiding.
Currently, there are four global navigation satellite systems (GNSSs) that can provide global coverage, including two fully operational systems (the United States' NAVSTAR GPS and the Russian Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS)), and two partially developed systems (the Chinese Compass navigation system and the European Union's Galileo positioning system).